These patches are fed either directly via contacted lines, e.g., microstrip lines at the edge, or through the substrate via feedthroughs into the patch area or within the multilayer substrate having a suitable layout via field coupling. Additional elements like a “superstrate” (planar dielectric plate at a certain distance to the patches) or a “polyrod” are used to attain a narrower antenna lobe characteristic.
The antennas are covered with a radome as mechanical protection against the environment (rain, snow, dirt, rockfall, . . . ). In special cases, the function of the superstrate is integrated into the radome by suitable geometry and material selection.
Complementary systems are also familiar, in which in the layout, the patches are metal-free, and the surrounding area is conductive.